Ice cream machine



Patented June 25, 1946 UNITED STATES PATENT foFFlcE ....lchfm.

This invention pertains to an ice cream machine, used in the continuous production of ice cream or frozen confection, wherein a suitable,

mix is introduced at one end of the machine and the frozen productv in edible condition is discharged at the other end thereof.

This invention is more particularly directed to a. mechanism which will continuously process an ice cream mix by centrifugally maintaining the particles of the mix in a thin film about a freezing surface and continuously scraping or peeling thev thin frozen film produced thereby from said freezing surface, and carrying it by such scraping and peeling action to the discharge end of the machine, whereupon it is discharged in finished edible form. As a result of such action the finished product is developed with a velvety texture of only approximately twenty-five percent overrun as compared with the usual fty percent overrun, but without being compressed, packed or re-frozen. Thus the product maintains its original soft texture as compared with a frozen crystal texture of the higher overrun re-frozen ice creams.

'I'his mechanism is so designed that the ice cream mix is kept in constant motion on the freezing wall of the machine, and the layer of mix on the wall is such as to eect proper heat transfer at such a rate that the freezing time is reduced to a minimum., The pitch of the scraping and feeding blades, and the angular velocity of said blades is such that the mix is moved parallel to the axis of the-mechanism at such velocity as to arrive at the discharge end at the instant freezing is completed.

'I'he period that the product remains in the machine is estimated to be from ten to fifteen seconds within which time full freezing of the product is completed, instead of the eighteen to forty-eight hours formerly required to freeze ice cream. Thus, the freezing time, with the consequent crystal growth, is greatly reduced.

'I'he full nature of the invention will be understood from the accompanying drawing and the following description and claims:

Fig. 1 is a central longitudinal section through the machine.

Fig. 2 -is a section taken on Fig. 1. v

Fig. 3 is a section taken on the line 3-3 of Fig. 1.

Fig. 4 is a side elevation of the scraper blade with its bearing in section.

Fig. 5 is an enlarged section taken on the line 5 5 of Figui.

the line 2 2 of 3 Claims. (Cl. 62-114) In the drawing there is illustrated a machine embodying the invention comprising a base I for supporting a horizontally-disposed cylindrical. housing I I. Said housing embraces at one end a minorcompartment t2 separated from a maior compartment I3 by a separating wall I4. The maior compartment I3, between the wall I4 and the discharge end of the machine,- encloses a refrigerating or freezing cylinder I5, said lcylinder being provided witha pair of. spaced concentric walls between which refrigerant carrying tubes or passages I6 are provided. Mounted axially of the cylinder I for rotation therein, there is a 'drive shaft I 'I supported by a bearing I8 at the discharge end of the housing II and by bearing I9 in the partition wall I 4.

0n the extension of the shaft I'I there is pro- I vided a driving pulley mounted in the compartment I2 and driven by a belt 2| from a motor 22 supported upon a frame 23 in the base of the compartment I0. The motor drive and belt are so designed as to drive the shaft I1. at about 350 R. P. M. Also, mounted within the base I0 there is a. compressor 24 connected with the refrigerant passages or pipes I6 for refrigerating the internal freezing surface of the freezing cylinder I5. In this connection, it is desirable to maintain the inner freezing surface of said cylinder at approximately ve degrees Fahrenheit. The ice cream or frozen confection mix is contained in avessel 25 mounted on the top of the housing II and communicating with a hopper 2B through an orice'controlled by a valve 21. The hopper 26 communicates With the interior of the cylinder I5 through a discharge opening 28 in the partition wall I4. At the other end or discharge end of the cylinder there is a diaphragm supporting the bearing I8 in which there is a discharge orifice 3|! communicating with an exteriorly and forwardly extending discharge spout 3I.

The shaft I1 carries within the major portion of the cylinder a series of dametrically opposed scraper blades 32 extending at an angle to the shaft with their outer edges curved to conform and lie adjacent the inner wall of the cylinder I5 to effect a scraping action about the freezing surface. Each blade is carried by a hub 33 through a reduced end portion 34, said hub being keyed or otherwise secured to the shaft I 1 for rotation-therewith. The length of the respective hubs is such that they abut each other end to end, each adjacent hub carrying its blade at about a sixty degrees angle to the preceding and following blade. As shown herein there are six such blades carried by the shaft in overlapping rela- 3 tion relative to each other, progressively spaced at sixty degree intervals about the shaft and freezing wall of the cylinder. The rearwardmost blade rotates adjacent the wall Il to pick up the mix as it is introduced into the cylinder through the orince 28.

By centrifugal force due to the rapid rotation thereof, the mix is spread about the freezing wall in a thindllm, suchthat it is rapidly frozen. But such frozen nlm is continuously scraped by the respective blades, and due to their angular disposition carried forwardly from one blade to the next. Thus. the centrifugal force applied to the mix not only maintains it in freezing contact with the wall of the cylinder. but itis caused to constantly` move ,thereabout and forwardly along the freezing wall to the forward or discharge end.

At vthe discharge end of the cylinder and adjacent the forwardmost of said blades there is a helical feed; screw I5 keyed to and rotatable with said shaft for gathering the frozen mix and feeding it through the discharge orice l0 'into the spout' 1,3 Il. Within said spout there is also provided a helical feed screw 38 keyed to and rotatable wltli said shaft. which -receives and carries the nished product forward for discharge from the machine. g

In view of the above, it will be notedthat the mix is maintained at all times distributed about the freezing wall of the cylinderin a thin nlm such that theparticles will freeze upon being thrown against said freezing surface. vbut which are constantly being scraped or peeled therefrom and moved forwardly from one scraping blade to the next while maintained in contact with the freezing surface by centrifugal force. Such centrifugal forcegkeeps the frozenv particles moving 0f the freezing wall until they are gathered by the, discharge screw 3! and.. fed thereby. from the machine., Thus, the mix is so frozen as it emergesfromgthe machine that it is immediately infe'dibie condition and requires no further freezing4v action.

. VIl'ieinvention claimed is:

,1. -Aimachlr'ie for producing. edible frozen ,confaction' in eontinuous operation, including a cylindricalA freezing chalutier' for continuouslyv receivir at one end a mix to be frozen and continuously.. u u 1 edible frozen confection at the otherend thereof, a motor driven shaft mounted forrotation of said chamber.V a series of scraper blades mounted radially about end thereof, and means for continuously discharging the frozen confection from said last mentioned end of said chamber.

2. A machine for producing an edible frozen confection in a continuous operation, including a cylindrical freezing chamber for continuously receiving at one end a mix to b e frozen and continuously discharging edible frozen confecwthe frozen mix conveyed thereto by said scraper tion at the other end thereof, a shaft rotatably mounted axially of said cylinder, means for rotating said shaft, and a series of scraper blades progressively mounted along said shaft to extend at an angle to the axial center thereof and in scraping relation with the surface of said chamber, each of said blades extending through an arc adjacent the surface of said chamber and in staggered relation to each other with the combined arcs through which the staggered blades extend co-extensive with the circumference of said chamber.

3. A machine for producing an edible frozen confection in a continuous operation, including a cylindrical freezing chamber for continuously receiving at one end a mix to be frozen and continuously discharging edible frozen confection at the other end thereof, a shaft rotatably mounted axially of said chamber, means for rotating said shaft, a series of scraper blades mounted in staggered relation along said shaft to be rotated thereby, said blades extending at an angle to said shaft and curved to conform to the curvature of said chamber throughout their length, a hopper communicating with one end of said chamber through which material to be mixed is continuously introduced therein to be simultaneously scraped from and conveyed along the wall of said chamber toward a discharge end thereof. a discharge screw mounted on said shaft adjacent theA discharge end of said chamber and a. discharge feed screw extending from the end of said shaft for receiving and continuously discharging blades and feed screw.

FRANK THOMAS. 

